About Me

Friday, November 6, 2009

After almost three years of blogging about sour beer (among other things fermentational) I think most of what I have learned about brewing them at home is buried somewhere in the roughly 250 posts on this site. That said there isn't anywhere on the blog where the bulk of my opinions and experiences have been coalesced for easy reference. I did put up a lengthy post about Brettanomyces a year or so ago, but that covered just one aspect of sour beer production.

What follows is essentially based solely on my experiences, so I won’t talk too much about things I do not have first hand experience with (like biology, pH levels, traditional practices etc…). Enjoy the data dump and please let me know if I failed to cover any topics that you think should be covered here.Base beer (brewday): In brewing sour beers and tasting many those made by the great number of American craft and homebrewers now trying their hand at it I have realized that you really don’t need to do anything special on brew day. Pretty much any well made base beer can serve as the foundation of a sour beer. The only beers to avoid souring are those that are aggressively bitter/roasty/spiced because these flavors will be exaggerated by the low finishing gravity of a sour beer.

You can use the same basic techniques during the mash/sparge/boil that you would for any other style; you don't need special procedures unless you are trying to replicate a classic/historic style (turbid mash for a lambic, no/short boil for a Berliner Weisse etc…). The only thing I would suggest in general is to try to mash a bit hotter than you would otherwise to ensure that there is plenty of residual extract left for the other microbes to chew on after the Saccharomyces is finished.

I have not found aged hops to be a necessity for any sour beers including inoculated-lambics. Since you are adding the microbes yourself you do not need to worry about protecting the beer from wild invaders as lambic brewers must when they are slowly cooling their wort in a coolship, exposed to the microbe-laden air. If you are looking to do a spontaneous/ambient fermentation then aging hops is something you should look into (several years before brewing...).

I do not do much with the water for my sour beers. Just enough to control the mash pH if need be. I do not see a need to mess around with the flavor ions (chloride, sodium, sulfate) in a beer that is already so complex.

Types of Microbes (bugs): Just like a regular beer brewer's yeast (Saccharomyces) is responsible for most of the alcohol production. The following microbes are responsible for the bulk of the souring/funking after that:

Brettanomyces (Brett) – The king of wild yeasts in the brewing world. It helps to breakdown dextrins (chains of sugars too long for Saccharomyces to ferment) and can add a wide range of characteristic esters and phenols to sour beers. These can range from nice ones like pineapple, apple, and pear; through ones that may or may not be appreciated like horse blanket and farmhouse/barnyard; to the vile smoky, Band-Aid, and fecal batch ruiners. These flavors depend mostly on the strain of Brett, but are also influenced by the types of acids and alcohols available.

Pediococcus (Pedio) – Produces most of the lactic acid in most sour beers. It often takes several months to really get working. Certainly strains can cause your beer to become “sick,” that is to become very viscous for a period of time (this has only happened once to me, but it passed after a couple months leaving a nicely sour beer). It can make your beer taste buttery for a time as well, but the Brett will clean this up in time (never use Pedio without Brett). Pedio also plays a role is the production of some traditional sausages.

Lactobacillus (Lacto) – The only time lacto plays a big role is in Berliner Weisses, the rest of the time the IBUs are high enough to keep it at bay (>8 IBU). It can sour a beer faster than Pedio, and is also the dominant player in yogurt production.

Acetobacter – Generally its role is kept to a minimum. It needs oxygen to convert the ethanol (alcohol) into acetic acid (vinegar). That should be some good motivation to keep your airlocks full and your barrels topped off. You can always add a bit of acetic character by adding some vinegar at bottling.

There are plenty of other minor microbial players (particularly in spontaneous fermentation), check out Wild Brews for a more comprehensive listing and descriptions of them all.

I like to use a combination of commercial cultures and bottle dregs (the fresher the better). In general it seems like the cultures sold by Wyeast and White Labs are less aggressive than those from bottle dregs, but they serve as a good base since you can't be sure what you are getting out of a bottle. Getting a wild range of microbes into your beer will give you a better chance at a balanced character and a relatively quick aging period. Here is a listing of beers with harvestable dregs that might be helpful.

Sanitation: These days I keep a second set of post-boil plastic (tubing, auto-siphon, bottling wand, bottling bucket, and thief) for my sour beers. There is no need to have a separate mash tun, boil kettle, wort chiller, or anything else that touches the wort when it is still hot. I do use the same pool of Better Bottles for fermentation and glass bottles for storage for all of my beers.

I clean all of my equipment with a long soak in hot tap water and OxiClean Free. Once it is completely free of visible debris I rinse it in hot water, then soak it in cold water and either Iodophor or Star-San (I alternate them to keep the microbes well behaved). I have had two infected batches over the five years I have been homebrewing, but these may or may not have been the result of sour beers (the first one probably was, but I suspect the second one was not).

There is no reason to segregate your fermenters into different areas during fermentation/aging. I have my clean and funky beers on different sides of the same room just to ensure I don’t disturb the sours while I am moving the clean beers around.

Inoculation: I have gotten the best results adding all of the microbes at the start of the fermentation together with the primary Saccharomyces strain. I don’t generally make a starter for the bugs unless I am using pure cultures (for something like a 100% Brett beer). This is because the different microbes have different required conditions for growth. Yeast strains (including Brett) need oxygen, Pedio on the other hand can’t deal with oxygen. pH can also be an issue since the acid produced for bacteria can damage yeast cells (remember this when considering waiting to pitch a primary yeast to give the bacteria a head start).

Pretty much any standard yeast will do for primary fermentation. I have made great sour beers with American/English/Scottish/Belgian Ale, German Lager, and Saison strains. Some character from the primary yeast may remain in the finished beer, but most of the esters will be destroyed by the various other microbes (primarily Brettanomyces) over the long secondary fermentation. The biggest impact the primary yeast will have on the finished beer is the attenuation level (low attenuating strains will leave more sugars for the other microbes leading to beers with more sourness and funk).

I have not gotten enough sourness by doing a clean fermentation followed by microbes in secondary. This seems to work in barrels where the bugs are receiving some oxygen through the wood, but in a carboy the resulting beer generally lacks the sour assault that I crave. Adding microbes after primary fermentation is a fine idea if you just want some funk because Brett seems to be able to produce esters without a lot of gravity change.

I usually rack sour beers on the same sort of schedule I would a regular ale. I wait until primary fermentation is mostly complete and a good deal of the yeast/trub has settled out (2-3 weeks). Then I rack to a Better Bottle (or barrel), add the oak (if any), and slap on a stopper and airlock. Not much more to it than that.

If after 6 months or so the beer still has not shown any signs of souring I will often add the dregs from a few more bottles or sour beers to try to kick things off. As a last resort I may also add some malt extract to feed the microbes.

I would save ambient fermentation for after you get a good number of sours going. I have not tried it, so for the time being I don’t have much to say about it except that it is riskier than pitching known cultures either from a lab or bottle dregs. Even the best lambic breweries blend most of their barrels to reduce variability, if you try an ambient fermentation try to get several going so you have some blending options.

You can and should repitch yeast cakes from sour beers. Each time you repitch you will get more funk and sourness because the bacteria will grow faster than the yeast. It does not have a huge batch to batch impact in my experience, but it is something you will notice if you do for multiple batches. I generally only repitch 1-2 times, but that is more because I only generally want to do some non-sours as well. I have a friend who has been repitching and saving the same mixed culture for years without any problem.

Wood/Oak: A classic component of sour beers is the wood (almost always oak) barrel. Ideally you would get a group of friends (or a big enough system) and brew enough to fill an entire used commercial barrel (50-60 gallons). Used wine and bourbon barrels are relatively cheap and easy to find (generally for around $100). While this may seem like a lot of beer and effort, in my experiences using full sized barrels can create sour beers with flavors that are simply not possible in any other way.

However I realize that this is not an option for everyone on every batch (including me). You should also consider:

Small barrel – I have not used these, but for better or worse they will let in proportionally more oxygen and lose more beer than a large barrel due to their higher surface area to volume ratio and thinner staves. The smaller the barrel the more this will be a concern.

Oak cubes/chips – Cubes/beans are your best bet because they take longer to give up their flavor due to their lower surface area. Around an ounce of cubes is a good place to start for a mild oak flavor. I boil them for about 10 minutes to removes some of the harsh fresh oak flavors that are usually stripped out by whatever is in the barrel before the beer. Sour beer can be pretty delicate and thin and it can be easily overwhelmed by harsh tannins or oak flavors. You can always add more after a few months if you want more oak character.

If you want to mimic wine/bourbon/port/brandy barrel aging you beer just soak the cubes in the alcohol before adding them to the beer (adding some of the alcohol of choice straight to the beer can also help boost this character). In general wine pairs best with sour beers, but a spirit can work well with bigger/bolder sours.

Wooden dowel, chair leg, peg - I played around with these for awhile, but never got results I couldn’t replicate with cubes. In my experience this setup can cause problems due to pressure build-up and cracked carboy necks due to the wood swelling. You can get around some of these problems by putting the oak through a stopper, but so far I haven't tasted a beer to make me think it is worth the effort.

Aging Vessel: If you aren't going to go with a barrel, there are several options to consider when deciding what vessel you want to age your sour beer in. Since the beer will age for so much longer than a standard beer things that wouldn't matter otherwise like the amount of oxygen that can diffuse through the material start to matter.

Better Bottle - What I use because they don't have the risk of breaking that glass carboys do. I also like the wider opening for getting fruit or hops in/out. They may let a negligible amount of oxygen in, but opening the stopper once will let more in than months of aging.

Glass Carboy - Just make sure you don't break one full of year old sour beer. The big advantage of these is that no oxygen can get in and they are easy to sanitize.

Bucket - I have yet to try aging a sour beer in one, but my friends who have do not seem to be getting objectionably acetic results as some people suggest (due to their high oxygen permeability). It may depend on things like temperature and specific microbe varieties. I also don't like the fact that you have to open them to look at the beer.

Conical/Keg - I don't use either, but the advantage of stainless is that like glass it is easy to sanitize and impervious to oxygen. If I had the money for a conical I probably wouldn't tie it up for several years with beer. A keg on the other hand seems like a fine place to do your sour beer fermenting if that is something you are interested in if you don't mind the obstructed view.

Aging: The longer you can age a sour beer in the fermenter the better, as they will almost always improve for a couple years. A moderate temperature is best in my experience (anywhere from the low 60s up into the 70s). A higher temperature will encourage more rapid souring, while a lower temperature will lead to a more balanced (less aggressive) beer.

A pellicle is a sign that there is oxygen in the head-space more than anything else. I have had fantastically sour/funky beers that never grew more than a light skin, and terrible beers that grew huge pellicles because too much oxygen was getting in. In general it is not something I would worry about too much either way (unless you are trying to brew a clean beer).

Just like any other beer you are best off aging sour beers where they get as little light as possible (I generally just use the boxes they come in or a pillow case with a hole cut to let the airlock through). It is also nice if you can keep them somewhere out of the way so they are out of sight and out of mind, making it easier to wait for them to age.

Fruit: Pretty much any fruit can work in the right sour beer. That said berries (sour cherry, raspberry) and stone fruits (apricot, peach) are the classics. They have a good balance of acidity, sweetness, and flavor. For the most part I like getting fresh fruit from the farmer’s market, but whatever is the most cost effective and tasty for you will work. For small fruits/berries I simply freeze them (which breaks their cell walls) until I am ready to add them to the beer. I let them defrost in a fermenter before racking the beer onto them. For larger fruits I will generally slice them up, then either freeze them or give them a bit of a muddle with an auto-siphon before racking a beer onto them.

In addition to adding a distinct flavor, fruit adds sugar, and acids as well. Most of the sugars added by the fruit are eaten by the bugs and critters which in turn cause them to produce more acidity and boost the production of other flavorful byproducts. The acids add a different character to the sourness since they are either malic or citric, both of which are a bit sharper than the lactic acid produced by the microbes in beer (malolactic bacteria will convert malic to lactic acid, so that is something to consider if you do not like the acid character of a fruited sour beer). In addition to their main constituents fruit also adds anti-oxidants, that’s right the same compounds that help prevent damage to your DNA from free-radicals also prevents oxygen molecules from creating off-flavors in your beer as it ages.

The acid of the beer really helps to make the fruitiness pop in a way that most "clean" fruit beers do not. The actual amount of fruit you need will depend on the variety of fruit, quality/freshness, base beer, and amount of fruit flavor you are aiming for. In general .5 lbs per gallon is the low end (good for assertive fruits like raspberry), and 2.5 lbs/gal is the high end for more subtle fruits, or if you have a bigger/darker base beer.

You will not get a sweet-fruity sour beer unless you kill the yeast and bacteria present using heat/chemicals/filtration before adding the fruit (this is what Lindemans does to make their lambics). If this seems too difficult you can add fruit juice to a plain sour beer in the glass (this is a good way to soften the beer for people who do not like something so dry and sour).

I generally like splitting a batch leaving half plain and adding fruit to the rest. This way I get two beers for the effort of one. It also makes for some interesting comparisons. Sometimes I like the fruited half more, other times the plain portion does it for me. I usually wait for at least six months before adding fruit, this gives me a chance to taste the beer and see which fruit I think would work well with it and it give the bugs a chance to get established so they are the ones fermenting the fruit sugars and not the primary yeast.

Bottling: Before bottling I wait until airlock activity has ceased, the gravity has not changed in at least a month, and the flavor is where I want it. I have never had an issue bottling while my beers still have a pellicle, but it can be an indication that something is going on. I would also be cautious bottling any sour beer with a gravity over 1.010 (unless it has a high ABV, or had other extenuating circumstances).

I generally reyeast with wine or neutral ale yeast at bottling. 2 grams of dry yeast rehydrated in 90-100 degree water is my standard rate for 5 gallons, but a little extra won't hurt anything. This ensures timely carbonation and not much change in flavor immediately after bottling. I generally use cane/beet/table/white sugar, it is cheap, effective, and doesn’t impart a flavor of its own. Candi and corn sugars are also fine choices, but tend to be a bit more expensive. I try to avoid using any variable agricultural products for priming like honey, maple syrup, or malt extract since it adds some guesswork (particularly when you are talking about a multiple microbe culture).

Some sour beers, particularly those aged in wood barrels or with the oak dowel/peg can be completely flat at bottling time. This is different than the usually assumed .5-.8 volumes of CO2 most priming calculators assume the beer is holding onto. As a result if your beer tastes wine flat you should consider adding some extra priming sugar (or be willing to accept a lower carbonation level than the your calculations might predict).

The carbonation level is up to you. Higher carbonation tends to increase the sense of acidity (dissolved carbon dioxide is carbonic acid) and give you the impression of body in very thin beers. In general I aim for moderate-low carbonation, but that is the way I like most of my beers. In the end it is just about what you think would taste good for your beer.

In my pale sour beers (especially those with wheat) I often get an odd cereal/cheerio finish for a few months after bottling that wasn’t there in the bottling bucket. It fades with time, but it is annoying while it lasts. In general if a sour beer doesn’t taste good give it more time (recently the brewer at Bullfrog Brewery told me how terrible his Gold Medal winning Beekeeper Honey Sour Saison was for several years, to the point he considered it lost, before it turned the corner).

Once the beer is bottled it will age like any other. Lower temps will slow aging, while higher temps will produce faster changes in the flavor. It is worth hanging onto bottles for many years. Most of my sours seem to be getting better and better as time goes on, some are now at nearly three years in the bottle.

General Tips: Be patient. Try to avoid taking samples too often, it introduces oxygen and steals good beer from your future self.

Get a new sour beer going every few months to build up a pipeline if you can. It is easy to look forward a few months to the next beer that will be ready, but it will drive you insane thinking about the fact that the beer you just brewed won't be ready to drink for at least a year. If you have a big enough system it just steal 5 gallons (or even less if you have some smaller fermenters) of wort now and then to sour. Having plenty of beers souring also opens up the world of blending (which pretty much every good production sour brewery does) when you have multiple batches ready around the same time.

Don’t skimp on ingredients. Spending a bit more now is worth it in the end, especially when you are investing such a huge amount of time/effort/thought into a beer. This is especially true of things like fruit, spices, and sugars, go to places that specialize in the ingredient, Ethnic Markets, Spice Shops, Farmer's Markets etc...

Make friends with other homebrewers interested in sours, particularly thosewho livenear you. Try their beers and have them try yours, some of the best sours I have had have been fermented in the basements and closets of other homebrewers.

Try as many commercial sour beers (for inspiration and microbes) as you can and ask questions of any commercial brewer who makes sours you enjoy. Most of them are very passionate and happy to help an equally passionate homebrewer. Asking about technique rather than recipes will generally get you more useful information.

Take as many notes on your beers as you can. These will help you to avoid mistakes or recreate successes in the future. With sour beers your technique evolves slowly since the feedback loop takes years instead of weeks like clean beers. My sours have steadily gotten better, but I still have beers aging that I made mistakes (or miscalculations) on that I have fixed in more recent batches.

If you want a hoppy sour beer, go with dry hops right before bottling (or in the bottle or keg). This will give you the mature acid/ester profile with the fresh hop kick.

Mike, We are planning what will be my first barrel aged sour out here in Portland. I need to go back and read your posts but I am wondering on the wine barrel flanders you did:1) Temp control? Basement or garage?2) To top-up, or not to top-up?

The Flanders and the Wee are both in my friend Nathan's basement (no intentional temp control other than that).

We topped off initially after the active fermentation ended, but after that we did not do any topping off. The beer does not have a noticeable acetic character, so it does not seem to have caused a problem.

I was just interviewed for an upcoming issue of Zymurgy on barrel beers, so look for that as well (not sure exactly what they are going to be using from my ramblings).

Wow, I must say, I have been browsing this blog for over a year now, and have been very inspired. After reading this long post, I decided to actually comment. This blog is BY FAR the best homebrewing beer blog I have EVER read. Fantastic work, keep it up

how long do you normally let your oak cubes sit in the beer? and does it depend on if they are soaked in wine or not? and the same for fruit? have you seen any varying results as far as time goes from a week with fruit to a month or so? - ottovon

I let the oak sit in for the whole souring period. That is why I go on the low-ish end for oak amount, you can always add more closer to bottling if you want more flavor. Doesn't matter whether or not I have soaked the cubes.

For fruit I generally go for a couple months. That gives plenty of time for the bugs to eat whatever sugars they provide.

Mike - thanks for putting all your thoughts together in one place. I've read this blog pretty closely over time as well as some of your beeradvocate oldsock postings and even babble belt stuff, so alot of the advice was familiar but great to have it all in one place. I am on sour batch #9 now (first 6 bottled) but have also done about 4 other batches in the vein of Orval. It is addictive and you are a great resource.

As far as questions go I have added extra carboys and would like to have several sours ageing at once, do some blending, etc. To store that many carboys, in addition to my non-sours, I'd like to put them in spots like the garage (cool but fairly constant temperatures) or the back room of the flat (cold at night but can get pretty hot on a sunny day).

Are both bad ideas? One better than the other? I don't want the cold of the garage to slow the souring / ageing process, but I imagine that is safer than the temperature variations of the back room. But while most beers hate temp. variations I recall that some Belgian breweries have wide temp. swings. I do live in San Francisco so temp. swings are mild relative to most of country. Thanks - Gilman (Gilmango on BA)

I am curious, you said in this post that you rack your sours on a similar schedule that you do your regular ales. I also have heard the contrary that you should leave them on the cake for 1+ years. Can you give a little more insight. This has always been something I was unsure of.

Leaving a sour beer in primary is an option, and a classic component of Lambic fermentation. It tends to give a funkier/brettier character that some people enjoy (as the yeast cells break down the Brett absorbs some of the nutrients released). Personally, I tend to like “cleaner” sour flavors so I rack off the yeast cake. I do leave my Lambics in primary, but so far I haven’t made one that I’ve been especially happy with. It would certainly be an interesting side-by-side to do with a 10 gallon batch.

What exactly do you mean by "You will not get a sweet-fruity sour beer unless you kill the yeast and bacteria present using heat/chemicals/filtration before adding the fruit"? How do you recommend killing the yeast/bacteria present in primary or secondary before adding fruit using homebrew means?

Exactly, fruit contains lots of simple sugars that the microbes used to chewing on long complex chains will quickly gorge themselves on. If you want a sweeter fruit beer you might be better off just bottling it without adding fruit, then blending with juice to taste in the glass.

Best write up I've seen! I do have one question, though. When the beer is aging in a glass/better bottle, what is the best way to taste the beer? Removing the airlock will let oxygen in and if a pellicle has formed I've always read that you don't want to disturb it. This has always been a mystery to me. Thanks again for this excellent guide!

I've never had an issue pulling samples exactly what you are describing. The pellicle reforms quickly, and I've never had an issue with acetic acid production. CO2 is heavier than air, so quickly opening the bung will not flood the fermenter with oxygen. What will get you acetic acid letting your airlock run dry (if you use a 3 piece even running low will let oxygen flow in). Only pulling a smaple once every couple months helps as well.

You mention that you repitch your sour yeast cakes multiple times, and that these give better results than the original pitch of bottle dregs. I assume what you repitch is NOT from the primary (which would be mostly the primary saccharomyces strain), but rather whatever critter mix is at the bottom of the secondary? As such, this cake has been sitting for a year or two, does it need to be reactivated in a starter before being repitched? Off topic: please write the book you're thinking about writing, and have Brewers Publications publish it, it will be a hugely valuable addition to the brewing literature.

The results from repitching aren't necessarily better, just more sour/funky. In some cases that is better, in others it is worse. I've pitched both primary and secondary yeast cakes. Pitching the primary cake has a good chunk of other microbes, and can certainly work (although since you don't know the results of the first batch it is hard to judge). If you are pitching the secondary yeast cake I would also add a healthy pitch of a Sacch strain, a year or two in the high alcohol low pH environment of a sour beer will leave those cells in bad shape (while the Brett and lactic acid bacteria will be fine).

The book is still well in the works. I'm almost done with the research phase, so soon I'll be reaching out to brewers directly for tips/quotes/pictures etc... Still not sure whether I'll go the BA route or self publish, I'll need to look into what they are offering.

Realize this is an older post but I thought it was most appropriate for a 'general' sour beer related question.

I am about to bottle my first sour (excluding Berliner-Weisse). It is based off of your temptation clone, I used cabernet soaked oak instead of chardonnay. It was fermented with Roeselare in the primary and lots of bottle dregs (Russian River, Jolly Pumpkin and more).

Gravity is down to 1.002-1.003 and it tastes great, I am anticipating bottling it in about 3 weeks. I am debating wether or not to "re-yeast" at bottling time. I am not concerned about rapid carbonation; I care more about it becoming fully carbonated eventually.

Are there any downsides you can think of for using a champagne/wine yeast to aid in bottle carbonation? I wouldn't imagine it would have any significant effect on flavor but if there is any benefit to letting the brett work on it over time then I would consider that too.

Do you think that priming with a sacch strain reduces the potential for long-term bottle aging vs. letting it slow condition with brett/bugs?

Thanks for the writeup, I have read it several times and its been very helpful.

I don't see any drawback to pitching a bottle conditioning strain except slightly more sediment in the bottles. The beers will still evolve over time. It is more about how soon you want to drink the beer, in addition to taking longer to carbonate non-repitched beers also tend to develop and then lose some odd flavors after bottling (my pale sours especially get sort of a wheat-cereal flavor for ~3 months after bottling).

I just read the post about brewing sour beers, and I am planning on giving it a try. I was curious if sealing all but one of the end of a 5 gallon wooden barrel with a wood sealer would keep it from evaporating too much of the beer and letting too much oxygen in. By my calculations this would give a five gallon barrel the same surface area to volume ratio as a 53 gallon barrel, as far as the oxygen permeability. You would still have the beer in contact with the wood and that may give it an overly oaky flavor, but I was thinking that if you ran some barrel clean through it a coulpe times it might knock that oaky flavor down. I was just wanting some input before purchasing a wooden barrel.

I would worry about putting anything on a barrel that wasn't food grade (which I would assume includes wood sealer). You might be able to get away with coating the barrel in paraffin wax, but I’m not sure it is worth the effort. I’d probably just age the beer in a carboy until the gravity is stable, and then put it into the barrel until the wood/acetic character is to your liking before bottling. Blending is also a good option, you could over-oak a beer and then use it to add oak character to other glass/plastic aged beers.

Honestly for your first try you’d probably be better off just using a carboy, while I love barrels, the results from using carboys with oak cubes are nearly as good (the wood character just isn’t quite as complex).

Results are the best proof, but I'm curious about the differences between a clean sacch primary followed by dosed secondary method vs. simultaneous sacch + bugs primary method. You've said here (and HBT and BYO) that you've gotten the best results with the latter method (simultaneously pitch of sacch + bugs, followed by racking to secondary for months/years). Obviously brett/lacto/pedio behave differently than sacch in terms of attenuation/expediency, food sources, staying in solution, etc., but part of me still has a hard time letting go of the notion that I'm racking out most or a majority of the bugs following that process. (I'm either missing something or manic, or both) At 3-4 weeks are the microbes working on enough long-chain sugars that the bugs will stay in solution?

The reason that brewer's yeast is so flocculant is that it has been selected generation after generation for that character (as brewers repitched or top cropped the highly flocculent cells were more likely to make it to the next batch). Brett has not had this selection pressure, and bacteria is very small compared to yeast and will not drop out unless given loads of time. What looks like clear beer can still have ~100,000 cell/ml, so don’t be worried (even a cold crashed beer has enough yeast in suspension to carbonate). If you are really worried, just suck up a bit of the trub into the secondary - a bit of dead brewer's yeast will only help the Brett.

Glad you enjoyed the article! I sent it in a few months ago and was starting to get worried that they weren’t going to publish it.

What would be your recommendation for reusing yeast from batch to batch? Would you suggest pitching a new batch of beer directly on top of all the yeast from the primary after racking your previous batch to secondary? Can you simply take dregs from the primary and pitch them into a new batch as you would commercial bottle dregs? Are the bugs in the primary even active enough to pitch given that they haven't yet soured the previous beer they were sitting in (primary for 3 weeks)? Thanks.

After three weeks you would be fine using a cup of the yeast slurry at the bottom of primary. I wouldn’t pitch the whole yeast cake, it would just be too many cells. You will most likely end up with more sourness in each subsequent repitch (all other things held constant) because bacteria reproduce much faster than yeast.

If you had an older batch that you wanted to harvest from, for example a secondary, then I would take a half cup of the slurry and augment it with a fresh pitch of brewer’s yeast to ensure a healthy start to fermentation.

as always michael, fantastic post. just wanted to post a thank you for documenting the poorly documented.

just getting ready to bottle a flanders and it sat in a barrel (5 gal) for 8 months (the barrel has been used for many things, this is the first sour so the oak characteristic is pretty spent)

i racked off to clarify and filled the barrel without cleaning.

just curious as to your thoughts, etc., about fermenting straight in a barrel (my house sour culture which has everything in it) - it'll be the 3rd "re-pitch" of this yeast which has turned out to be very aggressive.

other than making sure i top off as it ferments, i'm curious as to any opinions you might have about fermenting straight in a barrel.

Nathan and I did the primary fermentation for our wine barrel solera in the barrel and haven't had any problems with it. Leaving a sour beer on the yeast will give it a funkier more lambic-like character in my experience. As Saccharomyces dies it releases nutrients and fatty acids that will benefit the Brett and provide additional substrates for ester production.

I had a lychee sour a couple weeks ago that was mind blowing! I am new to brewing so I know this is way out of my league for now but thanks for such a great blog that I know I can come back to when I am ready. ;)

What's your procedure for adding more dregs down the line? Rack into a new carboy with the dregs in it or just toss them in? If its the latter, I'd think you'd want to give the carboy a shake, but then that brings up potentials oxidations issues.

Do you do anything to sanitize the oak, wine, or fruit when you add it? I understand the risk is not so bad being added later in the process, and that you are intentionally infecting the beer with other bacteria, but just curious if it's something you worry about.

Honestly just about all of the major spoilage microbes in beer are added intentionally to sour beers, so I don't worry about introucing more from wood/hops/fruit. Rather than controlling the microbes, the key is controlling the conditions (minimizing oxygen exposure for example).

Thanks for the great article and for your amazing blog in general! I have just started down the road of sour beer brewing, and have a question. I started my primary fermentation "cleanly," with the White Labs Belgian Ale yeast, and planned to add the White Labs Belgian Sour Mix 1 in the secondary. I had a change of heart after I discovered and read this article, and decided to add the sour power earlier to achieve more funkiness. So I pitched it about 24 hours into fermentation, when things were really cooking (constant bubbles from blowoff tube). Immediately after I pitched, things came to an abrupt halt. No bubbles. Nothing. That was 48 hours ago. Did I kill the batch? I was thinking that the sour guys would slowly takeover as the clean yeast gracefully finished the lion's share of the primary fermentation; I wasn't expecting things to just stop. Any thoughts or advice? Thanks for any help!

Mike, That cheerio/cereal flavor you get in young bottles-- do you think it's low levels of diacetyl? I have a similar taste in my sours, and it almost has a caramel note to it. A lot of off-tastes can come across differently at low concentrations. The fact that it gets "cleaned up" also would point towards diacetyl.

I do have a couple questions:- How soon after bottling to you typically sample the first bottle of a wild or sour beer? I have a gueuze (actually unblended lambic) in bottles, and I am DYING to pop one. It's been 25 days.

-Do you have a solution to pellicles forming in the bottle? I did a saison which I finished with bottle dregs in secondary for a few months, and it formed a pretty nasty skin, and hasn't really dissipated with time, chilling, or agitation. I can purge the bottles with CO2 before bottling, but this seems in opposition to the rustic nature of these beers. Would waiting longer to bottle avoid a pellicle?

Coincidentally, I opened my first bottle of gueuze on Friday and I am becoming more confident that the taste I get is diacetyl. It does taste to me like breakfast cereal, but in this, beer, which has a LOT of this taste at this point, it also has a bit of a butterscotch character to it. The last beer I had with this character cleared up after about 3 months or so.

Next time you taste a young sour of yours, Mike, ask yourself if it's diacetyl. You and I may not be having the same fermentation byproduct, of course.

Agreed, lactic acid bacteria need quite a bit of residual gravity to create their acid, something few Brett beers have. Never had an issue using the same gear for sour and funky beers. No harm in doing some extra cleaning/sanitation before bottling the barleywine. Good luck!

Hi Mike. I've been following your blog for a while now and you've inspired me to brew my first sour, a flanders red. I plan to use the Wyeast Roeselare blend in the primary without any other clean yeast. Would you recommend me to rack to a secondary or could I leave it to age on the yeast cake?

I tend not to keg sours because after all the time/effort, I want to enjoy them over a couple years. However, I have force carbed a couple of dry hopped sours with generally good results (I have a blended sour dry hopped with Comet on now). No reason not to keg condition, but it would take longer (and I tend to keg sours beers best drank fresh).

Now something I can't seem to find the "answer" to...I pitched Brett Brux a month or so ago and my gravity most recently was 1.020. I'm trying a Supplication clone and the sample was smothered in Pinot Noir. Anyhow, what are the proper fermentation temps for Brett Brux / and White Labs Sour Mix (brett/lacto/pedio)? All I seem to find is "above 70" and that is only part of the answer.

Russian River ferments their sours in the low 60s to reduce the prevalence of Acetobacter. Aging in carboys, temperature is a much lesser issue because they are impervious to oxygen. I've had good luck with temperatures from the low 60s into the high 70s. Ideally you want daily stability, changes throughout the year are fine (and some lambic producers would argue beneficial), but you don't want wild swings that could confuse the microbes.

Theoretically a sour beer will last just as well in the keg as it will in the bottle. However, I find it easier to save more sour beers longer when they are in bottles than on tap. I also like knowing exactly how much I have left. Natural conditioning tends to do great things for Brett character as well, and I like to witness the beer change over time at cellar temperature.

I tend to only keg sours I want to drink relatively quickly, often those I dry hop. I use a cobra/picnic tap. The only big issue with that is the drips into the kegerator, just be careful on where the bugs end up!

I have some ECY01 on the way, and I'm preparing to make my first Brett sour. This awesome post is my road map.

I'm confused, though, about aeration/oxygenation of the wort prior to pitching. Is it a desirable or necessary thing, as in a clean sacch. fermentation, or would it be a bad thing? (I'm thinking about what is said above about how pedio. can't handle oxygen, and also thinking about acetobacter.)

Pre-fermentation aeration is fine for a mixed fermentation sour beer, as the brewer’s yeast will use the oxygen before it leads to acetic acid production. I’ve heard Al suggest saving half of his ECY blends for pitching later to prevent issues with Pedio, but I’ve never had problems aerating and pitching the whole thing.

Thanks, Mike. I don't aerate all that much, anyway. Just 45 seconds of splashing and shaking.

My ECY01 arrived today, and the ice pack was still cold after 2,800 miles in transit! (Trenton NJ to Olympia WA.)

I'm excited to brew this beer--I'm looking at something like a sour Southern English Brown. A fellow on the BBB suggested that with ECY01, a whole lot of crystal malt wouldn't get in the way of complete attenuation. What's the most crystal you would use?

Actually, I was recently reading about an experiment conducted by someone on HBT did that didn't find much difference in the attenuation rate when adding crystal malt for clean beers. In the mash, most of the dextrins provided are further converted to fermentable sugars by the enzymes from the base malt. If saving more fermentables for the microbes is your goal, a higher mash temperature is the easiest way. Add the amount of crystal malt that you want from a flavor stand-point, probably in the 0-20% range.

Mike, I have a question regarding bottling. I will be bottling my first sour soon and I'm trying to decide if I should cork or cap. Is there a benefit to corking such as better long term aging or should I be ok with capping? Thanks again for your amazing blog!

Other than their snazzy appearance, there really isn't any advantage to corked and caged bottles. Most of my sours go into plain 12 oz capped bottles. If you were really pushing the carbonation, it would be safer to go with heavy champagne-style bottles, but for most sours (assuming the gravity is stable) that isn't necessary.

It is my understanding that Pedio prefers to work in a low-oxygen environment, but that the strains used in brewing aren't killed by elevated oxygen levels. If you were worried you could save half the dregs to add to the wort 12-24 hours after the initial pitch.

I finally got around to brewing a sour. Made a Flanders red a couple months ago that is aging in a better bottle right now. Pitched the Brewing Science B-73 Roselare Blend since the LHBS had a jug and gave it to me. Is it strange that it had some sour taste to it after 2 months (when I transferred it)?

Had so much fun I brewed a Berlinerweiss last week and pitched the apple juice starter and US-05. My ferm chamber smells like bananas. This is so addicting, especially for someone like me who enjoys brewing more than drinking.

Can't wait to get to Modern Times on my next trip down the road to SD.

Question about oak aging - can anyone reconcile the "directions" about using oak spirals stating that they should only be used for 6 weeks or it will over oak vs aging for 1 year+ in an oak barrel?

Chips / cubes may have a different "only use for x" timeframe, but I suspect it isn't too different any in any event is much less than what is stated to be fine for using oak barrels / what the lambic breweries do.

It all depends on the amount you add. Almost all barrel aged beers are aged in barrels that have already aged wine or spirits. This mellows the oak's character. Using a large amount of freshly toasted oak (like cubes or spirals) can quickly over-power a beer, just like a brand new barrel would.

I've never had a problem aging beers for a year or longer on oak cubes. I tend to use around an ounce for 5 gallons, and I'll steam or boil them for a few minutes first to remove some of the raw "lumber" aromatic from it.

Thoughts on a primary sour yeast cake? It has been in a brewing bucket with sealed lid. I originally intended on using it after transferring the original sour to secondary. Now I have both the primary and secondary about to open up. Bottle dregs in the primary with brewers yeast and bugs in the glass carboy secondary on oak chips. One year in the making and about to bottle for competition.

Should I reuse any slurry from the primary or will it be bad since it has been sitting for a year? How about the secondary? Pitch directly or save some slurry and add along side a brewers yeast?

Also, best carb volume for a sour stout using bottles and caps. No corker at this time.

I wouldn't trust the primary yeast cake after that long. A half cup of slurry from the secondary plus a fresh pitch of brewer's yeast is smart if you liked the result (and sounds like you did).

I like low carb, especially on something as complex and potentially sharp as a sour stout. I wouldn't go over 2.2-2.3 volumes of CO2. Hopefully the competition is a few months away, bottle conditioned sours often get a little weird for awhile.

Adding Champagne yeast isn't about your target carbonation, or current carbonation, but the health of the residual yeast. A couple grams of Champagne or wine yeast, rehydrated, goes into most of my sours at bottling. I find the standard priming sugar rate (determined by a priming calculator) works perfectly for most sours aged in carboys and better bottles. Anything barrel aged needs about .4 volumes extra to reach the target in my experience.

Best of luck! All of my Berliner have been mixed fermentation, never been a big fan of most sour mashed beers, even the best ones tend to have a hint of vomit to my nose.

Is it bad to move a fermenter around that is aging a sour beer? Will this mess it up or cause any weird flavors or anything? I have one of my fermenters aging a flanders red in my fermenation fridge and the only time I really dont want it in tere is when I throw in a new batch of wort to finish chilling it down to pitching temps. Its hotbhere in the summer so immersion chiller doesnt work as well :)Thanks for all the awesome info!

Also, how long would you suggest letting oak cubes sit on some pinot noir beforenthrowing it into beer to add an extra demension to the beer and forbthe oak to oick up some of that wine flavors? Thanks!

Not ideal to move a fermenting sour beer around, but only because it could sink the pellicle. If you aren't aging in a barrel, or pulling frequent samples, this probably isn't a major issue. Just be as gentle as you can.

I'd rather add the oak and wine separately. Just add the oak to taste and blend with the wine to get the flavor you want at bottling. Wine can oxidize and turn to vinegar, so if you want to soak oak in wine you'd have to be very careful about exposure to air. This isn't an issue when soaking in fortified wines or spirits, but still easier to add them individually as well.

I've brewed a few sour beers and I too have noticed the "cereal/cheerio" finish in them. You mentioned that the taste eventually went away. How long before the taste subsided? Did you always bottle and test over time? My beers are still in secondary, so wondering whether to transfer to bottle and age, or leave them in the carboy a while longer until the flavor goes away.

Hmm, I generally don't notice that flavor until after I bottle. Usually it takes 3-6 months to subside. If the gravity is stable, I can't think of a reason not to bottle. I don't beleive it is a character (like sulfur) that needs to be allowed to escape.

I'm getting ready to brew an RR Consecration clone and I want to make sure that it gets as sour as I'd like it to be. I've read several of your posts about this and I'm thinking about the best way to go about inoculating it. In order to get it as sour as possible, would you suggest introducing Brett, Lacto and Pedio as well as something like Wyeast 1762 in primary, then racking it over to secondary on currants and letting it go?

Sounds good to me. Russian River does lots of blending, they make a special super-sour "acid beer" that they'll blend in to add acidity for many bottlings. You might consider something similar, getting a really sour/strong beer is tricky without blending.

I am new to brewing sour/funky beers, but I had an extra gallon of a beer I made and decided to put it in a 1 gal glass carboy and throw Brett B. in there. I know it will add some funk but not really a true sour. For my first experiment I am not sure if I should now add some Pedio/Lacto or wait and see how it turns out. Any advice? the FG was around 1.011/1.012 and the Brett has been in there for about 3 weeks now.

Brett doesn't need much fermentable to make its character, Lactic Acid Bacteria do. Without knowing anything about the beer it's hard to give advice, but if you want some acidit you can try pitching Pedio (or dregs from a favorite sour beer). If not, wait until next time and aim for a higher FG pre-souring.

Mike very new to sour beer brewing and I saw you mentioned you don't suggest using a smaller sized oak barrel. Im only able to produce around 5 gallon batches at a time. Would you see a problem with using a 19L oak barrel to age in? Do you think that is too small and would introduce too much oxygen? Btw great write up and very helpful!

Since I wrote this post, I did get my hands on two 20 L oak barrels from a small distillery. Honestly the added effort and expense of using barrels didn't produce beers that were appreciably better than the dozens of sours I've aged in carboys with oak cubes. You can certainly give a small barrel a shot eventually, but I don't see a great reason to start there.

I have a question in regards to head space. I just began brewing sours, I do 5 gal batches. I just transferred one to secondary, and due to some loss I have way more headspace than I normally would. I shot some CO2 in there from my tank, but being that this is going to be aging for quite some time I am kinda worried. A thin film/crust has formed on top, which I believe is normal, will this protect it at all? Should I worry about this much space (prob 1 gal worth), add more co2, transfer to keg early?? Any guidance would be greatly appreciated. Thanks

Head space is a serious issue for barrels where the exposed wood can dry and let in excessive oxygen. In carboys, that isn't the case as long as you aren't pulling samples too often. Keep the airlock filled, and the stopper attached, and the beer will be fine!

Reading back through this I find myself a bit confused on the discussion regarding oxygen. Obviously with every other beer, oxygen is a bad thing once fermentation begins. But, here you say that you've noticed that you don't get a good sour character unless you pitch everything at primary because without secondary in oak barrels the brett doesn't get exposure to O2. This got me thinking if it would be beneficial to add a wee bit of O2 every month or so during aging but for the rest of the article you seemed very serious about limiting O2 exposure like you would any other beer. I guess I am just wondering if O2 is such a concern why do sours turn out better in barrels that let O2 in. Thanks for such a great post!

I view oxygen in sour beers in the same way I view water treatment: an opportunity to improve your beer somewhat, but at high risk if you aren't careful/accurate. Too much oxygen can quickly turn a beer acetic (vinegary) which also leads to the formation of ethyl acetate (solvent - nail polish remover in even moderate amounts).

Barrels must be topped off and temperature controlled to reduce this risk of excessive Acetobcter activity, impermeable fermentors are much more forgiving.

I wouldn't say carboy-aged beers are worse than barrel-aged, they simply require a slightly different process to produce optimal results.

Hello Mike.Thanks again for this inclusive post. Until I have a copy of your book, this will continue to be my go-to.

My question is about wood. I have four sour batches under my belt, and my process has been to let the beer sour for 12-18 months, and then add the oak (1 - 1.5 oz) for the final two months or so. I taste the beer, then bottle when the oak character reaches the level I want. I notice that you (and most others) add the oak at the beginning of the aging period.

I plan on using the latter method on my next beer, but wonder what may be the risks of adding the oak late. I have noticed some poor head retention in my sour beers, and wonder if the timing of the oak my be a factor.

I saw a mention of a Better Bottle in the article. Do you find it OK to age your sours in plastic fermenters for a year or more? I've done a few so far and seem to think I've had good results, but I'm wondering if plastic is still the no no it's often made out to be for long term storage.

Overall I thought this was a great article and blog…thank you and I just subscribed!

I am just getting into the world of sour beers after a week long trip to GABF 2014 and tour de Colorado. I want to start brewing them at home but have a time issue. I will be moving to one location in about 8-9 months and will only be there for about 9 months before moving yet again to a more long term location. A few questions/concerns that you may be able to help with:1. From reading your book and other online posts it seems like 1 year or more is the best time frame for a sour and that sours are ready when they determine they're ready. I want to experiment with these brews and do 2 three gallon split batches to mess around with different fruits, bottle dregs, oak, etc. Will a smaller 3 gal batch require just as much time (1 year) as a full 5 gal typical batch?

2. If I do jump into this and only have 8-9 mod and the beer doesn't taste ready, is it bad for the beer to be moved? I'm assuming yes but you never know. I would guess that all of the sloshing would disturb the pellicle and introduce oxygen in the beer. Not to mention the trouble of moving several carboys of beer.

I know this is a long term process that has the potential to yield some fantastic results if done properly and not rushed. On one hand I don't want to wait 18 months until I get to my long term location just to get started as that would mean 2.5 years until that first batch is in bottles. On the other hand, I don't want to rush the process and waste a potentially good batch of sour just because I want to have some soon (the next 9 months) rather than later (nearly 3 years).

Quick question. First time brewing a sour. I used a saison base, added Brett and harvested dregs from some Oude Tart and Quetsche Tilquin after a month.

It's been 4 months, and the pellicle has dropped. As soon as it dropped, I got a thin white film starting around the edges of the carboy, and slowly starting to cover the entire surface. Is this normal? I want to add oak cubes, and let it sit on them for a while, but I don't want to disturb what's going on. Advice? Much appreciate, and love your work!